B OpenNebula/one#6781: add issue 6781 in whats news file. (#3193)

Author: jloboescalona2

source/intro_release_notes/release_notes/whats_new.rst

@@ -51,8 +51,7 @@ Features Backported to 6.10.x
 
 Additionally, the following functionalities are present that were not in OpenNebula 6.10.0, although they debuted in subsequent maintenance releases of the 6.10.x series:
 
-- Feature 1
-- Feature 2
+- `Fix de-selecting hidden datatable entries <https://github.com/OpenNebula/one/issues/6781>`__.
 
 Other Issues Solved
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